"He maketh a path to shine after him; one would think the deep to be hoary."
The fossil remains of these reptiles are numerous, constituting a rich mine of scientific wealth, which has been but very lightly worked. Enough fossils can be obtained by future exploration to fill to overflowing all the museums of the land.
We have no means of computing how long the cretaceous sea existed, but we know that it passed away and was replaced by large fresh-water lakes, those of the plains being bounded on the west by the Rocky Mountains. Then succeeded an age of which we can catch but occasional glimpses, and our longing becomes intense that we could know more. We see a land fertile as the garden of Eden, surrounding beautiful lakes. The climate is delightful, and earth, air, and water, are full of life. Grand forests and flower-covered prairies nod and blossom under the kind caresses of Nature. Water fowls numberless plunge under and skim over the surface, and the songsters of the air warble forth their hymns of praise. Over the pastures and through the forests roam an animal multitude of which we can have but faint conception, but among the number we recognize the lion with his royal mane, and the tiger with his spots; and there also are the elephant, the mastodon, the rhinoceros, the wild horse, and the great elk.
After our return, the eminent naturalist, Prof. Edward D. Cope, A. M., visited the plains, and spent some time in careful exploration there. As he had previously received several fossils from us for examination, I communicated with him not long since, asking a record of his trip. This he very kindly consented to furnish, and, did space permit, I would gladly publish entire the matter which he has placed at my disposal. No apology can be necessary, however, for yielding to the temptation of devoting two or three chapters to a chat by Prof. Cope with my readers.
The manuscript, as it lies before me, is entitled: "On the Geology and Vertebrate Palæontology of the Cretaceous Strata of Kansas." Let us begin with "Part I—A General Sketch of the Ancient Life."
That vast level tract of our territory lying between Missouri and the Rocky Mountains represents a condition of the earth's surface which has preceded, in most instances, the mountainous or hilly type so prevalent elsewhere, and may be called, in so far, incompletely developed. It does not present the variety of conditions, either of surface for the support of a very varied life, or of opportunities for access to its interior treasures, so beneficial to a high civilization.
It is, in fact, the old bed of seas and lakes, which has been so gradually elevated as to have suffered little disturbance. Consistently with its level surface, its soils have not been carried away by rain and flood, but rather cover it with a deep and widespread mantle. This is the great source of its wealth in Nature's creations of vegetable and animal life, and from it will be drawn the wealth of its future inhabitants. On this account its products have a character of uniformity; but viewed from the stand-point of the political philosopher, so long as peace and steam bind the natural sections of our country together, so long will the plains be an important element in a varied economy of continental extent.
But they are not entirely uninterrupted. The natural drainage has worn channels, and the streams flow below the general level. The ancient sea and lake deposits have neither been pressed into very hard rock beneath piles of later sediment, nor have they been roasted and crystallized by internal heat. Although limestone rock, they easily yield to the action of water, and so the side drainage into the creeks and rivers has removed their high banks to from many rods to many miles from their original positions. In many cases these banks or bluffs have retained their original steepness, and have increased in elevation as the breaking-down of the rock encroached on higher land. In other cases the rain-channels have cut in without removing the intervening rocks at once, and formed deep gorges or canyons, which sometimes extend to great distances. They frequently communicate in every direction, forming curious labyrinths, and when the intervening masses are cut away at various levels, or left standing like monuments, we have the characteristic peculiarities of "bad lands" or mauvaises terres.
In portions of Kansas tracts of this kind are scattered over the country along the margins of the river and creek valleys and ravines. The upper stratum of the rock is a yellow chalk; the lower, bluish, and the brilliancy of the color increases the picturesque effect. From elevated points the plains appear to be dotted with ruined villages and towns, whose avenues are lined with painted walls of fortifications, churches, and towers, while side alleys pass beneath natural bridges or expand into small pockets and caverns, smoothed by the action of the wind, carrying hard mineral particles.